Fix duplicate output on console resize event

[o-sdn-o]

PR Summary

Fix the long-known issue of duplicate output.

• Fix false write operation rejection followed by retry on console resize event.
• Remove the workaround with ignoring the first console resize event. Prevent duplicated login message #426

PR Context

When a console resize event is received, the event handler sets errno to EINTR, which falsely causes a concurrently pending write operation to be considered failed and retried. This results in duplicate console output, as well as duplicate application requests. This duplication can lead to an infinite loop, since a duplicate request generates another console resize event, which triggers another duplicate request. This can occur, for example, when terminals generate a resize event when an application requests a switch between alternate/normal buffer mode.

Fixes PowerShell/Win32-OpenSSH#2275 and most of related issues.

Related to:

• Shell prompt repeating when using ssh in terminal microsoft/terminal#407
• ConPTY(?) inserts broken control codes into tmux sessions. microsoft/terminal#7185
• ssh newline problem microsoft/terminal#8278
• watch command doesn't work properly microsoft/terminal#8869
• Display problem when using "less" command microsoft/terminal#9431
• OpenConsole: Duplicate output lines when connecting to Ubuntu via SSH microsoft/terminal#15769
• Spurious OSC 11 when using tmux over Windows' SSH microsoft/terminal#18004
• Spurious OSC 11 command ends up writing to terminal or even executing as commands when opening vim microsoft/terminal#18714
• Printing specific sequence causes device attributes sequence to appear microsoft/terminal#19120
• Escape sequences like DA responses can end up fragmented across multiple TCP/IP packets microsoft/terminal#19282
• Receiving duplicated response for a single device attribute request microsoft/terminal#19345
• Using remote vim over Windows openssh inserts text into the file automatically microsoft/terminal#19577
• Random letters are inserted on startup microsoft/edit#243
• Extra c0c Inserted At Beginning of File in Windows Docker Container microsoft/edit#377
• Strange characters at the beginning of file when creating or opening (when SSH'd from WSL to Windows 10) microsoft/edit#414
• Bug: "c2c" letter on the first buffer text in Wezterm terminal microsoft/edit#508
• signs added, when editing via remote powershell on a core windows server 2022 microsoft/edit#674
• Tmux output numbers separated by semicolon at startup tmux/tmux#3880
• tmux prints random characters when starting or attaching tmux/tmux#4535
• Responses to DA, DA2, background color requests get passed on to the client on Windows Terminal tmux/tmux#4634
• 11;rgb:0c0c/0c0c/0c0c gets printed on terminal when tmux start... seems to be inserted by the bash shell tmux/tmux#4642
• Tmux output numbers separated by semicolon at startup tmux-plugins/tpm#272
• Ghost characters appear when running tmux in a Win10->Linux ssh session directvt/vtm#819
• MotD duplicated when called from PowerShell Core Win32-OpenSSH#1253
• Wrong CR/LF behavior in ssh.exe Win32-OpenSSH#1256
• Prompt is printed twice when exiting nano Win32-OpenSSH#1376
• Strange character sequences (ANSI escape sequences?) leaking into shell prompt when starting/attaching Tmux Win32-OpenSSH#2275 (comment)
• Prevent duplicated login message #426
• On windows terminal when ssh to a linux host it render error openai/codex#4759
• Frequently appearing These garbled characters 10;rgb:3b3b/3b3b/3b3b11;rgb:f8f8/f8f8/f8f810; openai/codex#5584

[o-sdn-o]

@microsoft-github-policy-service agree

[tgauth]

/azp run

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[boomshankerx]

This is infuriating. It's interrupting my entire workflow. Please make this a priority.

[diffuty]

All checks seem to be passing.
Curious what blocks reviewers from giving this PR a look ?